Ethylene polymerization in the presence of complex nickel catalysts containing a glycolic acid,thiogly colic,or thtolactic acid ligand

ABSTRACT

ETHYLENE IS POLYMERIZED IN THE PRESENCE OF A CATALYST WHICH IS THE REACTION PRODUCT OF A NICKEL COMPOUND WITH A LIGAND SELECTED FROM THE GROUP CONSISTING OF GLYCOLIC ACID, THIOGLYCOLIC ACID AND THIOLACTIC ACID. THE NICKEL COMPOUNDS COMPRISE OLEFINICALLY UNSATURATED COMPOUNDS OF FROM 2 TO 20 CARBON ATOMS. THE PREFERRED NICKEL COMPOUND IS BISCYCLOOCTADIENE-1,5-NICKEL.

United States Patent Oihce 3,661,803 Patented May 9, 1972 ETHYLENEPOLYMERIZATION IN THE PRESENCE OF COMPLEX NICKEL CATALYSTS CONTAIN- INGA GLYCOLIC ACID, THIOGLYCOLIC, OR THIOLACTIC ACID LIGAND Ronald Bauer,Orinda, and Harold Chung and Wilhelm Keim, Berkeley, Calif., and Henryvan Zwet, Amsterdam, Netherlands, assignors to Shell Oil Company, NewYork, N.Y. No Drawing. Filed Jan. 15, 1970, Ser. No. 3,199

Int. Cl. C0811 3/04 US. Cl. 252-431 C 11 Claims ABSTRACT OF THEDISCLOSURE Ethylene is polymerized in the presence of a catalyst whichis the reaction product of a nickel compound with a ligand selected fromthe group consisting of glycolic acid, thioglycolic acid and thiolacticacid. The nickel compounds comprise olefinically unsaturated compoundsof from 2 to 20 carbon atoms. The preferred nickel compound isbiscyclooctadiene-1,5-nickel.

A variety of polymerization catalysts, both homogenous andheterogeneous, has been utilized to convert ethylene into products ofhigher molecular weight. One widely used class of catalyst is theso-called Ziegler type which is the result of the reaction of a highervalence transition metal compound and a Group I, H or III metal alloy,hydride or organic derivative of the Group, I, II or III metal having anorgano-metallic bond.

The present invention is directed toward the polymerization of ethyleneand to novel compositions used as catalysts in these polymerizations.The catalyst composition of this invention is the reaction product of anickel compound and a ligand selected from the group consisting ofglycolic acid, thioglycolic acid and thiolactic acid. The nickelcompounds comprise an atom of nickel in complex with an olefinicallyunsaturated compound of from 2 to 20 carbon atoms. The preferred nickelcompound is hiscyclooctadiene-1,5-nickel.

United States Pat. 3,324,092, Naarmann et al., issued June 6, 1967, isdirected to a process for polymerizing olefins in the presence of achelate of a metal from Group I-B, II-B, IV-A, V-A, V-B, VI-B, VH-B orVIII of the Periodic System and an unsaturated aliphatic cyclichydrocarbon having to 12 carbon atoms in the ring. Compounds suitablefor the formation of the metal chelate compounds are compoundscontaining two functional groups which can become linked with metalatoms, one group being linked by main valences and the other bycoordinate bonds. These suitable compounds are fl-diketones, such asacetylacetonate, fi-ketocarboxylic esters, such as ethyland3-methylbutene-(l)-ol-(3)-acetoacetate, amine acids having two to sixcarbon atoms, such as glycine and histidine, hydroxyaldehydes, such assalicylaldehyde, and also o-aminophenol, o-aminobenzoic acid or4,5-phenanthroline (ophenanthroline).

The present invention is directed to novel catalyst compositions for thepolymerization of ethylene. These compositions have not previously beendisclosed in the art. The catalysts of the present invention are theproducts of the reaction of a nickel-olefin complex with an organic acidligand as described. It has surprisingly been found that only certainorganic acid ligands within this group are suitable for reaction withnickel compounds to produce active ethylene polymerization catalysts.Applicants have found that glycolic acid, thioglycolic acid andthiolactic acid are suitable ligands for producing catalysts of thegeneral description above for polymerizing ethylene to highly linearpolymer products. This observation is surprising in view of the factthat applicants have found that compositions from similar ligands,notably acetic acid, HSCH CH COOH, HSCH COOC H l-thioglycerol, HSCH CH(CH are not suitable catalysts for the polymerization of ethylene.

The catalysts of the present invention are described as the product ofthe reaction of a nickel compound comprising an atom of nickel incomplex with an olefinically unsaturated compound, preferablybiscycloactadiene-1,5- nickel (O), with a liquid selected from the groupconsisting of glycolic acid, thioglycolic acid and thiolactic acid.

The nickel compound employed as a catalyst for the polymerizationprocess may be described as comprising an atom of nickel from abiscyclooctadiene nickel (0) complex or like complex of nickel (O) ornickel (I) further complexed with a ligand selected from the groupconsisting of glycolic acid, thioglycolic acid and thiolactic acid. Thispreceding description is suitable but is not preferred for the reasonsdiscussed below.

Although it is not desired to be bound by any particular theory itappears likely that the catalyst molecule undergoes chemicaltransformations during the course of the polymerization reactionpossibly involving coordination and/0r bonding of ethylene to the nickelmoiety. However, it appears likely that the acid ligand remainscomplexed and/or chemically bonded to the nickel moiety during thecourse of the reaction and that this complex of nickel and acid ligandis the effective catalytic species of the polymerization process. In anyevent, the ligand is an essential component of the catalyst and providedthe nickel catalyst contains the required acid ligand, the nickelcatalyst may be complexed with a variety of additional organiccomplexing ligands.

The catalysts of the present invention are typically formed in situ inthe reaction medium but the present invention encompasses thenickel-acid catalysts as described regardless of what sequence is usedfor catalyst preparation and polymerization. Whether the catalyst isformed and perhaps even identified prior to its use as a polymerizationcatalyst or is formed in the reaction medium while the polymerization isproceeding, its exact active form during the polymerization reaction isnot precisely ascertainable. For this reason the catalyst is preferablydescribed as the product of the reaction of the nickel compound with theligand selected from the group consisting of glycolic acid, thioglycolicacid and thiolactic acid as described.

When the catalyst is characterized as the product of the reaction of anickel compound with the acid ligand wherein the nickel compound isselected from the group consisting of nickel (O) compositions and nickel(I) compositions, the characterization does not encompass nickel whichis reducible to a lower positive valence state. In the case of the Ni(I) compositions, the nickel is capable of being reduced to a lower(nonpositive) valence state which is zero (0). The nickel (O)compositions comprise an atom of nickel complexed or chemically bondedto sufiicient complexing ligands to satisfy the coordination number ofthe nickel atom which typically but not invariably' is four. However,because of the difiiculty in ascribing oxidation states or valences totransition metalcontaining catalysts, the catalysts of the presentinvention are preferably defined in terms of reaction products as aboveor in terms of an empirical representation as described below ratherthan in precise bonding or oxidation state terms.

\In another manner of describing the catalyst of the present invention,the compositions are represented by the empirical Formula I:

(I) n )m wherein Z is selected from the group consisting of glycolicacid, thioglycolic acid and thiolactic acid, L is an olefinicallyunsaturated compound of from 2 to 20 carbon atoms, of up to 4 olefiniclinkages, and of up to 3 carbocyclic rings, 11 and m are selected fromnumbers of from 1 to 3 and the sum of n and m may be but is notnecessarily equal to 4. However, as pointed out above, it is preferredto describe the catalyst as the reaction product of the nickel complexand the acid ligand and it is to be understood that the composition asdepicted in Formula I is meant only to represent the empiricalcomposition and that the precise nature of the bonding between theglycolic acid ligand, thioglycolic acid ligand or thiolactic acid ligandand the nickel moiety is not definitely known. However, it is consideredlikely that the nickel is in a low valence state, e.g. zero-valent ormono-'valent nickel, which valence state is dependent on the nature ofthe chemical bonding between the nickel moiety and the ligand.

The organic complexing ligand L is an olefinically unsaturated compoundof from 2 to 20 carbon atoms, of up to 4 olefinic linkages and of up to3 carbocyclic rings. A particularly preferred class of olefinicallyunsaturated compounds are olefins of from 2 to 12 carbon atoms,represented by the Formula II:

wherein R and R" independently are hydrogen, alkyl, cycloalkyl, alkenyl,cycloalkenyl, aralkyl, aryl or alkaryl of up to 8 carbon atoms, with theproviso that the R and R" groups may together form a divalent aliphaticmoiety of from 2 to 10 carbon atoms of up to three additional olefinicdouble bonds as the sole carbon-carbon unsaturation.

Illustrative olefins of Formula II therefore include ethylene,propylene, Z-butene, 1-pentene, l-hexene, l-octene, l-de'cene,butadiene, isoprene, 1,3,5-octatriene, 1,3,7-octatriene, cyclopentene,cycloheptene, cyclopentadiene, cyclohexa-1,3-diene, cycloocta-1,5-diene,cyclooctatriene, cyclooctatetraene and cyclododecatriene.

The particularly preferred organic complexing ligand L for thisinvention is cyclooctadiene. This moiety is unique and givesparticularly good results in the polymerization of ethylene as will beshown later. The cyclooctadiene, in bonding terms, is vr-bonded to thenickel as opposed to the sigma bonding between nickel and for instancecyclopentadienyl chelates or at least is bonded to the nickel in amanner different than the chelate bonding between cyclopentadiene andnickel.

The nickel composition employed in the polymerization process isprepared by a variety of methods. In a preferred method, the catalystcomposition is prepared by contacting an olefinic-nickel compound andthe acid ligand. The preferred class of olefinic-nickel compounds usefulas catalyst precursors are zero-valent nickel compounds represented bythe Formula III:

(III) R wherein RCH CHR" has the significance as defined in Formula II.Illustrative nickel compounds of Formula III are thereforebiscyclooctadiene nickel (O), biscyclooctatetraene nickel (O), andbis(1,3,7octatriene) nickel Another class of olefinic-nickel compoundsuseful as catalyst precursors is vr-allyl nickel compounds wherein thenickel moiety is bonded to a wr-allylic moiety characterized bydelocalization of the electronic contribution of the vr-allyl moietyamong three contiguous carbon atoms. One suitable type of 1r-ally1nickel compounds is represented by the Formula IV:

wherein R and R" independently are hydrogen, alkyl, cycloalkyl, alkenyl,cycloalkenyl, aralkyl, aryl or alkaryl of up to 8 carbon atoms, Y ishalogen, preferably halogen of atomic number from 17 to 35 inclusive,i.e. chlorine or bromine, alkoxy or alkanoyloxy of up to 10 carbonatoms, and the dotted line designation represents the electronicdelocalization among the three illustrated contiguous carbon atoms, withthe proviso that R" together with one R may form a divalent hydrocarbylmoiety of 2 to 10 carbon atoms, preferably 2 to 5 and of up to 3additional olefinic double bonds. When considered as a Whole, preferred1r-allyl moieties have from 3 to 12 carbon atoms and are otherwise freefrom aliphatic unsaturation unless the qr-allyl moiety is part of aclosed ring system.

Illustrative of suitable 1rallyl nickel halides of the above Formula IVare ir-allylnickel chloride, 'lT-fillYlIliCkCl bromide, ir-crotylnickelchloride, 1r-methylallylnickel chloride, vr-ethylallylnickel chloride,ar-cyclopentenylnickel bromide, vr-cyclooctenylnickel chloride,wr-cyclooctadienylnickel chloride, ir-cinnamylnickel bromide,vr-phenylallylnickel chloride, vr-cyclohexenylnickel bromide,1r-cyclododecenylnickel chloride and wr-cyclododecatrienylnickelchloride. Although the complex of the above Formula IV and othervr-allyl nickel halides probably exist independently in the form of adimer, for convenience and simplicity the 1r-allyl nickel halides areherein depicted and named as monomeric species.

Other suitable ar-allyl nickel compounds of Formula IV arewr-allyl-nickel acetate, vr-methylallylnickelpropionate,1r-cyclooctanylnickel octoate, vr-allylnickel methoxyate and1r-allylnickel ethoxyate.

Another suitable type of ir-allyl nickel compounds useful as catalystprecursors is bis-1r-allyl nickel compounds represented by the FormulaV:

wherein R", R and the dotted line designation have the same significanceas defined in Formula IV with the proviso that R" together with one R ofthe same 1r-allylic moiety may form a divalent alkylene moiety of 2 to10 carbon atoms, preferably of 2 to 5. When considered as a whole,preferred ar-allyl moieties have from 3 to 12 carbon atoms and areotherwise free from aliphatic unsaturation unless the allyl moiety ispart of a closed ring system. Illustrative of suitable bis-vr-allylnickel compounds of the above Formula V are bis-vr-allyl nickel,bis-1r-methallyl nickel, bis-1r-cinnamyl nickelbis-1r-octadienylnickel,bis-1rcyclohexenylnickel, 1r-allyl-ir-methallylnickel, andbis-1rcyclooctatrienylnickel.

The catalyst composition is suitably preformed by contacting thecatalyst precursors in an inert diluent, e.g. diluents employed for thepolymerization process. In another modification, however, the catalystprecursor components are contacted in the presence of the ethylenereactant during the initiation of the polymerization process. By anymodification, the catalyst precursor components are contacted attemperatures from about 25 C. to C. In the reaction, the ratio of nickelcomponent to acid ligand can be between 0.5 :1 to 1:12 with a preferredrange of 1:1 to 1:4.

The nickel catalyst is suitably employed as an unsupported material. Incertain modifications, the nickel catalyst can be supported on aninorganic, solid catalyst carrier which is normally solid under reactionconditions and is heterogeneous, i.e. is substantially insoluble in thereaction medium. Illustrative of suitable inorganic, solid catalystcarriers are inorganic acidic oxides such as alumina and inorganicmaterials known as refractory oxides. Suitable refractory oxides includesynthetic components as well as acid treated clays and similar materialssuch as kieselguhr or crystalline macroreticular aluminosilicates knownin the art as molecular sieves. In general, synthetic catalyst carriersare preferred over natural occurring materials or molecular sieves.Exemplary synthetic refractory catalyst carriers include alumina,silica-alumina, silica-magnesia, silica-alumina-titania,silica-alumina-zirconia, silica-titania-zirconia,silica-magnesia-alumina and the like. Particularly preferred catalystcarriers are siliceous refractory oxides containing up to 90% by weightof alumina, especially silica and silica-alumina.

When the catalyst compoistion is supported, the proportion of catalystcomposition to carrier is not critical. In general, proportions ofcatalyst composition from about 0.01% to about 70% by weight, based onthe catalyst carrier are satisfactory, with amounts of from about 0.1%to about by weight, calculated on the same basis, being preferred. Thecatalyst composition is introduced onto the carrier in any suitablemanner. In one modification, the supported catalyst composition isprepared by intimately contacting the preformed catalyst composition andthe carrier in an inert diluent, preferably the same inert diluentemployed for preparing the catalyst composition. In anothermodification, the catalyst compositions can be prepared directly on thecatalyst carrier support surface by contacting the catalyst compositionprecursors in the presence of the catalyst carrier in a suitable inertdiluent.

The amount of catalyst composition employed in the polymerizationprocess is not critical. In general, amounts of catalyst compositionfrom about 0.001% by weight to about 100% by weight based on ethyleneare satisfactory with amounts from about 0.01% by weight to about byweight on the same basis being preferred. The ethylene is contacted withthe catalyst composition or the catalyst precursor components in theliquid phase in the absence or presence of reaction solvent or diluentwhich is liquid at reaction temperature and pressure. Illustrative ofsuitable diluents and solvents are aromatic compounds such as benzene,toluene, chlorobenzene and oxygenated hydrocarbons such as dialkylketones, e.g. acetone, methyl ethyl ketone and ethyl butyl ketone;cycloalkyl ethers, e.g. dioxane, tetrahydrofuran and tetrahydropyran;and acylic alkyl ethers, e.g. dimethoxyethane, diethylene glycol,dimethyl ether and dibutyl ether. Othes suitable solvents or diluentsinclude nitriles such as acetonitrile and propionitrile; dialkylamidessuch as dimethylformarnide; and dialkylsulfoxides such asdimethylsulfoxide. Still other suitable solvents or diluents comprisewater or water containing a portion of a polar organic co-solvent.Alkanes and alkenes, including cycloalkanes and cycloalkenes, of from 5to 20 carbon atoms such as butene-l, isopentane, pentene, cyclopentane,cyclohexane, isohexane, heptane, isooctane, decane, decene-l, dodecane,hexadecene and eicosane are also suitable reaction solvents. In somemodifications of the polymerization process, a portion of the productsuitably serves as reaction diluent and no added diluent is employed.When diluent is utilized, however, amounts up to about moles of diluentper mole of ethylene are satisfactory. Preferred reaction diluents andsolvents are aromatic hydrocarbons, lower dialkylsulfoxides, lowernitriles, alkanes, or mixtures thereof.

A particularly surprising aspect of the present invention is that thepolymerization reaction can be suitably carried out in water. Thus wateris a most preferred reaction medium for this invention. The water may,but does not necessarily contain a polar organic solvent. Suitablemixtures of water and polar organic solvent vary by volume from about20% to 80% organic solvent and from about 80% water to 20% The processis suitably conducted in an inert reaction environment so that thepresence of reactive materials such as oxygen is desirably avoided.Reaction conditions are therefore substantially oxygen-free.

The precise method of establishing ethylene/catalyst contact is notcritical. In one modification, the catalyst composition and the diluentare charged to an autoclave or similar pressure reactor, the ethylenefeed is introduced, and the reaction mixture is maintained withagitation at reaction temperature and pressure for the desired reactionperiod. Another modification comprises passing, in a continuous manner,the ethylene reactant in liquid phase solution in the reaction diluentthrough a reaction zone in which a supported catalyst composition ismaintained. By any modification, the polymerization process is conductedat moderate temperatures and pressures. Suitable reaction temperaturesvary from about 25 C. to 250 C., but preferably from 30 C. to C. Thereaction is conducted at or above atmospheric pressure. The precisepressure is not critical, so long as the reaction mixture is maintainedsubstantially in a non-gaseous phase. Typical pressures vary from about10 p.s.i.g. to 5000 p.s.i.g. with the range from about p.s.i.g. to 1000p.s.i.g. being preferred.

The polymerization products are separated and recovered from thereaction mixture by conventional methods such as fractionaldistillation, selective extraction, filtration, adsorption and the like.The reaction diluent, catalyst and any unreacted ethylene are recycledfor further utilization.

During the polymerization process ethylene is converted to principallyhigh molecular weight, polymer products, i.e. polyethylene. The productsare characterized by high linearity and crystallinity. Generally, theproducts ate characterized by a high molecular weight, a linearity ofless than 1 branch per 1000 monomer units and an inherent viscosity(0.10 g./100 ml. solvent at C.) of between 1 to 10 dl./ g. Theseproducts are materials of established commercial value. Thepolyethylenes can be used as wire and cable insulation, or for makingcontainers, pipes, housewares, filaments, films and coatings.

To further illustrate the improved process of the invention and thenovel catalyst composition, therefore, the following examples areprovided.

EXAMPLE I A catalyst mixture was prepared by reacting 0.115 g. ofthiolactic acid (Z-thiopropionic acid) with 0.373 g. ofbiscyclooctadiene-1,5-nickel (0) dissolved in 10 ml. of toluene. Thecatalyst was added to 135 ml. of dry toluene in a 300 ml. stainlesssteel autoclave. The reactor was sealed, purged with argon, andpressured to 2000 p.s.i. The polymerization was carried out withaddition of ethylene under a constant pressure of 2000 p.s.i. at ambienttemperature. After three hours the reactor was vented and a solidproduct was collected by filtration. There was obtained 1.3 g. of highdensity polyethylene having an inherent viscosity of 9.3 dl./ g. (0.3 g.polymer/ 100 ml. Decalin at 135 C.).

EXAMPLE II A catalyst solution prepared from 0.405 g.biscyclooctadiene-l,5-nickel (O) and 0.112 g. glycolic acid in 20 ml. ofdry toluene was charged to an 80 ml. stainless steel autoclave that hadbeen purged with argon. The reactor was initially pressured to 900p.s.i. with ethylene and heated to 65 C. The ethylene pressure wasmaintained at 1275 p.s.i. throughout 2 /2 hours of reaction time. Solidlinear polyethylene in amount of 1.55 g. was isolated by filtration andwashing with methanol.

EXAMPLE III A supported catalyst was prepared by admixing 2.0 g. ofmicrospheriodal alumina (calcined at 4000 C. for 4 hours in anatmosphere of nitrogen), 0.275 g. of biscyclooctadiene-1,5-nickel (O),0.100 g. of thioglycolic acid and 25 ml. of toluene for 15 minutes. Theresulting supported catalystwas filtered, washed three times withnhexane, and dried in vacuo. The dried catalyst and 25 ml. n-hexane werecharged into a metal reactor, and ethylene monomer was introduced to aninitial pressure of 750 p.s.i. The polymerization reaction was carriedout at 60 C. for 2 hours. The polymer formed was precipitated withmethanol, filtered and dried in vacuo. The yield was 8.25 g. of linearpolyethylene.

EXAMPLE IV A supported catalyst was prepared by admixing 12.0 g. ofmicrospheroidal alumina (calcined at 400 C. for 4 hours in an atmosphereof nitrogen), 1.65 g. of biscyclooctacliene-I,5-nickel (O), 0.452 g. ofthioglycolic acid and 40 ml. of toluene. The resulting supportedcatalyst was then filtered, washed three times with n-hexane and driedin vacuo.

The supported catalyst, 2.0 gm., and 30 ml. of dry nhexane was chargedto an 80 ml. stainless steel autoclave under a nitrogen atmosphere. Thereactor was pressured with ethylene to 900-1000 p.s.i. and reacted at 70C. for 1 hour. After cooling the reactor to room temperature, theunreacted ethylene was vented, and the resulting polymer was isolated byprecipitation in methanol. There was obtained 4.9 gm. of linearpolyethylene.

EXAMPLE V A supported catalyst was prepared by admixing 8.0 g. of acracking catalyst which contained 25% Al O /Si (calcined at 400 C. for 4hours in an atmosphere of nitrogen), 1.10 g. ofbiscyclooctadiene-l,S-nickel (O), 0.368 p g. thioglycolic acid and 56ml. of toluene. The resulting supported catalyst was filtered and washedthree times with n-hexane and dried in vacuo.

The supported catalyst, 1.0 gm., and 30 ml. dry hexane, were charged toa 80 ml. stainless steel autoclave under a nitrogen atmosphere. Thereactor was pressured with ethylene to 900-1000 p.s.i. and reactor at65- -4 C. for 1 hour. After cooling the reactor to room temperature theunreacted ethylene was vented and the resulting polymer was isolated byprecipitation in methanol. There was obtained 3.9 gm. of linearpolyethylene.

EXAMPLE VI A catalyst was prepared from the reaction of 4.5 gm. ofbiscyclooctadiene-nickel (O) and 1.66 gm. of thioglycolic acid in 80 ml.dry toluene under an argon atmosphere. The reaction mixture was stirredovernight at ambient temperature with the formation of a black complex.The resulting catalyst was isolated via precipitation with n-hexane,filtered, washed with n-hexane three times and dried under high vacuumat ambient temperatre. The catalyst yield was 2.33 gm.

The isolated catalyst, 0.14 gm. and 25 ml. of n-hexane was charged intoa 60 ml. stainless steel autoclave under a nitrogen atmosphere. Thereactor was charged with an initial pressure of 750 p.s.i ethylene, andthe polymerization reaction was carried out at 60 C. for 4 hours. Solidpolyethylene in amount of 1.3 gm. was isolated by filtration and washingwith methanol.

EXAMPLES VII TO IX TABLE Ex. Nickel compound Acid ligand Support VIIBisacrylonitrile Thioglycolic acid-.. Micro-spheroidal nickel. alumina.

VIII. Bis-w-allyl nickel do Do.

IX.-. Bis-x-methallyl Thiolactic acid 25% AlzOa/SiOe nickel. crackingcatalyst.

What is claimed is:

1. A catalyst composition which comprises the prodnot of reacting inliquid phase solution at a temperature of from about 25 C. to C. anickel compound represented by a formula selected from the groupconsisting of wherein R" and R independently are hydrogen, alkyl,cycloalkyl, alkenyl, cycloalkenyl, aralkyl, aryl or alkaryl of up to 8carbon atoms and Y is halogen of atomic number 17 to 53 inclusive,alkoxy or alkanoyloxy of up to 10 carbon atoms which the proviso that R"together with R may form a divalent hydrocarbyl moiety of 2 to 10 carbonatoms and of up to three additional olefinic double bonds, with a ligandselected from the group consisting of glycolic acid, thioglycolic acidand thiolactic acid, the molar ratio of nickel compound to ligand beingfrom about 0.5 :1 to 1:12.

2. The composition of claim 1 in which said catalyst is supported on aninorganic solid, carrier selected from the group consisting of inorganicacidic oxides and siliceous refractory oxides.

3. The composition of claim 1 in which said reaction of nickel compoundwith said acid ligand is carried out in the presence of ethylene.

4. The composition of claim 1 in which said nickel compound isbiscyclooctadiene-1,5-nickel (O).

5. A process for preparing acatalyst composition which comprisescontacting in liquid phase solution at a temperatune of from about 25 C.to 100 C. a nickel compound represented by a formula selected from thegroup consisting of:

wherein R" and R independently are hydrogen, alkyl, cycloalkyl, alkenyl,cycloalkenyl, aralkyl, aryl or alkaryl of up to 8 carbon atoms and Y ishalogen of atomic number 17 to 53 inclusive, alkoxy or alkanoyloxy of upto 10 carbon atoms with the proviso that R together with one R' may forma divalent hydrocarbyl moiety of 2 to 10 carbon atoms and of up to threeadditional olefinic double bonds, with a ligand selected from the groupconsisting of glycolic acid, thioglycolic acid and thiolactic acid, themolar ratio of nickel compound to ligand being from about 0.5 :1 to1:12.

6. The process of claim 5 wherein said contacting is carried out in thepresence of ethylene.

7. The process of claim 5 in which said nickel compound is reacted withsaid acid ligand in a molar ratio of nickel compound to acid of fromabout 1:1 to 1:4.

8. The process ofi claim 5 further comprising supporting said catalyston an inorganic solid carrier.

9. The process of claim 8 in which said carrier is selected from thegroup consisting of inorganic acidic oxides and siliceous refractoryoxides.

10. The process of claim 5 in which said nickel compound isbiscyclooctadiene-1,5-nickel (O).

9 10 11. The process of claim 5 in which said reaction is 3,379,7064/1968 Wilke 252-429 X carried out in water. 3,479,488 2/1970 Dawans eta1. 252-431 C X 3,522,283 7/ 1970 Wilke 252431 C X References CitedUNITED STATES P 5 PATRICK P. GARVIN, Primary Examiner 2,768,963 10/1956Reppe et a1 2s2 43 CX U95.

3,324,092 6/1967 'Naarman at X 252-429 R; 260439, 439 CY, 94.9 B, 94.9c, 94.9 1)

3,326,990 6/1967 Clank 252431 CX

